The research proposal involves the study of growth promoting factors extracted from mouse submandibular glands on the development and maintenance of orofacial tissues and structures. Specifically, epithelial growth factor (EGF) and mesenchymal growth factor (MGF) will be evaluated in respect to their ability to promote growth of tooth germs, oral epithelium, bone, and muscle. In vitro studies will be done using tissue culture cells and organ culture explants. In vivo studies will be carried out in mice.